Egypt displayed today newly discovered tombs more than 4,000 years old and said they belonged to people who worked on the Great Pyramids of Giza, supporting evidence that slaves did not build the ancient monuments.

The modest 9ft deep shafts held a dozen skeletons of pyramid builders, perfectly preserved by dry sand along with jars of beer and bread for the afterlife.

The mud-brick tombs were uncovered last week near the Giza pyramids, stretching beyond a burial site first found in the 1990s and dating to the 4th dynasty (2575BC to 2467BC), on the fringes of the present-day capital, Cairo.

The ancient Greek historian Herodotus once described the pyramid builders as slaves, creating what Egyptologists say is a myth propagated by Hollywood films.

Graves of the builders were first found nearby in 1990 by a tourist. Egypt's chief archaeologist, Zahi Hawass, said the finds show the workers were paid labourers, rather than slaves.

Hawass told reporters at the site that the find, first announced on Sunday, said the find sheds more light on the lifestyle and origins of the pyramidbuilders. Most importantly, he said the workers were not recruited from slaves commonly found across Egypt during those times. One popular myth that Egyptologists say was perpetrated in part by Hollywood held that Israelite slaves built the pyramids.

Amihai Mazar, professor at the Institute of Archaeology at the Hebrew University of Jerusalem, says that myth stemmed from an erroneous claim by the former Israeli prime minister Menachem Begin, on a visit to Egypt in 1977, that Jews built the pyramids.

"No Jews built the pyramids because Jews didn't exist at the period when the pyramids were built," Mazar said.

Dorothy Resig, an editor of Biblical Archaeology Review in Washington DC, said the idea probably arose from the Old Testament Book of Exodus, which says: "So the Egyptians enslaved the children of Israel with backbreaking labour" and the Pharaoh put them to work to build buildings.

"If the Hebrews built anything, then it was the city of Ramses as mentioned in Exodus," said Mazar.

Dieter Wildung, a former director of Berlin's Egyptian Museum, said it is "common knowledge in serious Egyptology" that the pyramid builders were not slaves. "The myth of the slaves building pyramids is only the stuff of tabloids and Hollywood," Wildung said. "The world simply could not believe the pyramids were build without oppression and forced labour, but out of loyalty to the pharaohs."

Hawass said the builders came from poor families from the north and the south, and were respected for their work – so much so that those who died during construction were bestowed the honour of being buried in the tombs near the sacred pyramids of their pharaohs.

Their proximity to the pyramids and the manner of burial in preparation for the afterlife backs this theory, Hawass said. "No way would they have been buried so honourably if they were slaves."

The tombs contained no gold or valuables, which safeguarded them from tomb raiders throughout antiquity, and the bodies were not mummified. The skeletons were found buried in a foetal position – the head pointing to the west and the feet to the east according to ancient Egyptian beliefs, surrounded by jars once filled with supplies for afterlife.

The men who built the last remaining wonder of the ancient world ate meat regularly and worked in three-month shifts, said Hawass. It took 10,000 workers more than 30 years to build a single pyramid, Hawass said, a tenth of the workforce Herodotus wrote about after visiting Egypt around 450BC.

Hawass said and that evidence indicates they the approximately 10,000 labourers working on the pyramids they ate 21 cattle and 23 sheep sent to them daily from farms.

Though they were not slaves, the pyramid builders led a life of hard labour, said Adel Okasha, supervisor of the excavation. Their skeletons have signs of arthritis, and their lower vertebrae point to a life passed in difficulty, he said. "Their bones tell us the story of how hard they worked," Okasha said.

Wildung said the find reinforces the notion that the pyramid builders were free men, ordinary citizens. "But let's not exaggerate here, they lived a short life and tomography skeletal studies show they suffered from bad health, very much likely because of how hard their work was."